Breakpoints and Halting in Distributed Programs

Interactive debugging requires that the programmer be able to halt a program at interesting points in its execution. This paper presents an algorithm for halting a distributed program in a consistent state, and presents a definition of distributed breakpoints with an algorithm for implementing the detection of these breakpoints. The Halting Algorithm extends Chandy and Lamport’s algorithm for recording global state and solves the problem of processes that are not fully connected or frequently communicating. The definition of distributed breakpoints is based on those events that can be detected in a distributed system. Events that can be partially ordered are detectable and form the basis for the breakpoint predicates, and from the breakpoint definition comes the description of an algorithm that can be used in a distributed debugger to detect these breakpoints. Index Items Distributed Programming, Distributed Debugging, Halting Algorithm, Distributed Breakpoints.